1. Technical Field
The present invention relates to an imaging unit, a manufacturing method thereof, and a liquid ejecting apparatus provided with the imaging unit.
2. Related Art
A liquid ejecting apparatus in which an imaging unit is provided on a supporting portion which supports a medium, a texture of the lower surface of the medium which passes over the medium supporting portion is imaged by the imaging unit, and the transport amount of the medium is detected based on the image that is obtained through the imaging is known as a liquid ejecting apparatus which ejects a liquid such as an ink from an ejecting unit onto a medium such as paper. In such a liquid ejecting apparatus, an opening portion for allowing light from the imaging unit to radiate toward the bottom surface of the medium is formed in the supporting surface of the medium supporting portion (for example, refer to JP-A-2013-119439).
As illustrated in FIG. 15A, an imaging unit 200 of the related art is provided with a cylindrical lens holder 210, which forms a portion of a lens barrel, and an optical member 220 (a lens), which is fixed to the lens holder 210 using an adhesive 230. The lens holder 210 includes an abutting portion 212 and a through hole 213. The abutting portion 212 protrudes inward from an inner circumferential surface 211 and the optical member 220 is abutted thereto, and the through hole 213 penetrates, in the radial direction of the lens holder 210, a portion that is adjacent to the abutting portion 212 in the axial direction of the lens holder 210. In the imaging unit 200 of the related art, the optical member 220 is fixed to the lens holder 210 by injecting the adhesive 230 into the through hole 213 in a state in which the optical member 220 is inserted into the lens holder 210 and abuts the abutting portion 212 (for example, refer to JP-A-2014-6476).
However, as illustrated in FIG. 15B, in the imaging unit 200 of the related art, the adhesive 230 which is injected into the through hole 213 enters a gap between an outer circumferential surface 221 of the optical member 220 and the inner circumferential surface 211 of the lens holder 210. Since the through hole 213 directly communicates with the gap between a top surface 212a of the abutting portion 212 and a bottom surface 222 of the optical member 220, there is a case in which the adhesive 230 enters the gap between the top surface 212a of the abutting portion 212 and the bottom surface 222 of the optical member 220. In this case, there is a concern that the optical member 220 will incline toward the lens holder 210 due to the adhesive 230 lifting the optical member 220 from the abutting portion 212.